Phase III GRAPPA Trial Endorses ATLG in Stem Cell Transplantation

Data from the Phase III GRAPPA trial, presented at EHA 2026, confirm ATLG (Grafalon®) as the standard of care in matched unrelated donor stem cell transplantation. The study did not prove the non-inferiority of post-transplant cyclophosphamide (PTCy) compared to ATLG regarding overall survival. Additionally, ATLG demonstrated lower non-relapse and infection-related mortality rates.

ATLG showed a two-year non-relapse mortality of 7%, compared to 13% in the PTCy group. Infections primarily caused the higher non-relapse mortality in PTCy recipients. Despite higher rates of GvHD with ATLG, there was no negative impact on survival outcomes.

With 75% overall survival at two years for ATLG recipients, the trial supports ATLG's continued use and emphasizes the importance of balancing GvHD prevention with survival and infection outcomes. The GRAPPA trial underscores ATLG's role, with ongoing improvements in GvHD management encouraged.